O-higu are tiny, bluish-colored soybeans unique to the Ryukyu islands that play an essential part in Ryukyuan and Okinawan cuisine. In comparison to foreign soybeans, it has a higher protein content, more soybean oligosaccharides, and elastic processing features.
O-higu has long been a popular item for "Shima-dofu (tofu)" and "Shima miso".

Shima-dofu is a fundamental component of traditional Ryukyu/Okinawan cuisine, and it varies from regular tofu in its preparation and ingredients, such as the use of saltwater.
Shima-dofu and yushi-dofu are also available fresh and warm only in Okinawa.
There is also a difference in appearance. While a standard piece of Japanese tofu is approximately 400 grams, Shima-dofu is quite bigger, weighing over 1 kilogram.

Following World War II, the arrival of imported soybeans and crop conversion in agriculture dramatically reduced the area of o-higu cultivation. However, there is a growing movement, based in Hantagawa, Naha City, which was formerly a tofu production hub, to revitalize the seeds and food culture that the region has loved for a long time. At the Hantagawa Community Center, events are conducted to celebrate and further promote the production of Shima-dofu using o-higu grown in a home garden, known as "Ataigwa" in Okinawan language, and bringing varied meals that utilize o-higu and enjoy together.